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I>OBK 8UPi>l.Y OF MO|«TitWAIi. 


WIWtilAH O^lfBIS, Ml)., M.B.aP.i Low>., 

I /Proleworol the laiHttite* of MiXlidtifi, IfeCHH UnlyewHy; Ii«JtureS: on 
Helminliiolegy, aibnttna ?«|er|iMrr College. ^ 


A. w. ci#iiK:tfT (f^AwaiKCE, iiAsa.), 


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I>ORK Supply of Montreal. 


WILLIAM OSLER, M D., M.R.C.P., Lond., 

Professor of the Institutes of Medicine, McGill University ; Lecturer on 
Helminthology, Montreal Veterinary College. 


StudfSDt. Montrf al Veterinary. College. 

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B. Q. R.- 



JANUARY, 1883. 




In the interests of public health, it is a matter of great im- 
portance that the food supply of cities should undergo strict 
supervision, with a view of excluding possible sources of disease. 
In this country, the department of the civic governments relat- 
ing thereto cannot be said to be conducted on model prin- 
ciples. Speaking of Montreal, meat inspection consists in the 
examination of the carcasses of all animals exposed for sale or 
killed at the abattoir, and its superficial character is clearly 
shown by the results of this investigation. 

It is to be remarked that, in the matter of meat inspection, 
there are some affections in which an ante-mortem examination 
will be of most service, and an animal may be condemned as 
unfit for food, the meat of which, when dressed, might pass even 
a careful inspector. There are other affections which, interfering 
but slightly with the general healthfulness of an animal, render 
its flesh in the highest degree unfit for food, even though it 
may, on superficial inspection, look healthy enough. 

• Bead hrfore the Medico- Chirurgical Society of Montreal and the Board of Health, 



The flesh of swine forms one of the great staple articles of 
food in the community, and, fresh or salted, constitutes a very 
considerable proportion of all meat eaten. The hog is omnivorous, 
a dirty feeder, refusing nothing, and, regarded from this stand- 
point, we do not wonder that in the sanitary enactments of 
Moses it was excluded, though cloven-footed, in the list of animals 
permitted to be eaten. Vile feeder though it be, the hog has the 
power of converting, in the laboratory of its tissues, even refuse 
and garbage into a flesh most wholesome as well as toothsome. 
Who does not remember Lamb's charming " Dissertation on 
Roast Pig," and though he speaks of the suckling, most of us 
can agree with him when he says, " Pig — let me speak his 
praise — is no less provocative of the appetite than he is satisfac- 
tory to the criticalness of the censorious palate. The strong man 
may batten on him, and the weakling refuseth not his mild juices." 
The hog 7'" not subject to many diseases which interfere 
with the market value of the flesh. Pig-typhoid or hog cholera 
is the only extensive epizootic disease among them in this coun- 
try, and by interfering with nutrition and producing emaciation 
renders the flesh unsuitable for food. The injurious efiects which 
follow the eating of the flesh of diseased animals are really not 
much known. The juices of the stomach are so powerfully 
antiseptic and corrective, that the meat, after cooking, is usually 
digested without difficulty. The Highland shepherds are stated 
to eat, without ill effects, the flesh of animals which have died of 
anthrax. In the case of pork, it is not so much the fresh or salted 
meat which has been known to produce sickness as when it is made 
into sausages and brawn (head cheese). Many cases of serious 
illness have been excited by eating these articles. This is not sur- 
prising to anyone who has watched their manufacture, particularly 
sausages. In many establishments the odds and ends go for the 
mince meat, and, too often, bits of old meat which is just begin- 
ning to turn. The experience is only too common of tasting in 
a mouthful of sausage the disagreeable flavor of a morsel which 
is high, i.e., is in the initial stages of putrefaction. The septic 
matter, if abundant, or, perhaps, if produced by bacteria of a 
special variety, may excite severe intestinal symptoms, and even 



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cause death. In Whitechurch, England, there has recently been 
a local epidemic produced by eating brawn. 

In relation to public health, the diseases of the hog are of 
small matter in comparison with the parasites which infest its 
flesh, and which, eaten by man, may produce serious or even 
fatal affections. It is as a protection against tliese that an effec- 
tive meat inspector may do good service in the community, and 
annually prevent many cases of illness. To obtain evidence of 
the prevalence of parasites in the pork supply of this city, one 
thousand animals have been examined, with tiie results here 
stated. Of the parasites which infest the hog, only three are of 
importance in this connection— the Trichina spiralis, the Ot/s- 
ticercus cellulosce, and the EcUnococcus. We shall consider 
these in order. 

"An extremely minute nematoid helminth, the male in ita fully developed 
and sexually matured condition measmin- only one-eighteenth of an inch, 
while the perfectly developed female reaches a length of about one-eighth 
of an inch ; body rounded and filiform, usually slightly bent on itself, 
rather thicker behind than in front, especially in the males ; head narrow, 
finely pointed, unarmed, with a simple, central, minute oval aperture; pos- 
terior extremity of the male furnished with a bilobed caudal appendage, 
. . . female shorter than the male, bluntly rounded posteriorly, eggs mea- 
suring jiiVs of an inch from pole to pole ; mode of reproduction viviparous." 


Since Zenker, in 1860, discovered that this worm produces 
a severe malady in man, a degree of interest has been attached 
to it, not exceeded by any known human entozoon. The record 
of epidemics of it sends a thrill of horror through a community 
out of all proportion to the gravity of the disease ; and naturally 
enough, for the very thought of myriads of these little worms 
boring and eating the flesh is particularly repulsive, recalling 
the tragic fate of Herod, on whom the worms are stated to have 
held an ante-mortem feast. The hog is thenatural bearer of the 
trichinae, which exist in the flesh, coiled up between the muscle 
fibres, and are so minute that they cannot be seen on ordinary 
inspection, but require the use of the microscope. In this state 
they are undeveloped or immature sexually, and may remain 
for years in the muscles of the animal without undergoing de- 


,»Vl3^..fR'^'HS*W^ :»'•«»•'«' 


generative changes. Pork containing them and eaten raw, in 
any form, or partially cooked, produces disease in the following 
way : the little worms escape in digestion, pass into the small 
intestines, grow rapidly, become sexually mature, and assume 
the form of intestinal trichinae. The females are impreg- 
nated, and the ova develop into minute embryos, which are born 
alive and free. This process occupies two or three days, and is 
usually accompanied with some intestinal irritation. The number 
of embryos will vary with the number of worms ingested and which 
reach maturity. They immediately burrow through the walls 
of the intestine, reach the connective tissues of the abdomen, 
and penetrate the muscles in all direction, and when numerous 
reach even those most distant. In this migration they produce 
irritation, fever, and constitutional disturbance proportionate 
to their number, and the severity of the symptoms may be such 
that death may follow, though the percentage of fatal cases is 
small, only about 1.5. 

Record of Investigation. — One thousand hogs were examined, 
chiefly at the Dominion Abattoir, during the past six or eight 
months. There was no selection made, but the carcasses were 
taken indiscriminately, as they were found at the time of the 

Method. — It has been satisfactorily shown by many observers 
that the pillars of the diaphragm are the most suitable muscles 
for examination, not alone because portions can be removed with- 
out disfigurement or loas, but chiefly from the fact that here, if 
anywhere in the body, the parasites will be found, as these muscles 
lie in the direct route from the intestines. The examination was 
made with No. 2 Obj. (Verick) and No. 1 Ocular, magnifying 
about 60 diameters. Small clippings of the muscle were made 
lengthwise, then placed on the slide, and pressed out with the 
top cover until thin enough for the purpose. In only four out 
of the one thousand animals were the parasites present in the 
diaphragm, and we may take this as representing the actual ratio, 
though possibly they may, in one or two instances, have existed 
in other muscles and not in the portions examined. As to the 
number in the infested bits, in one case there were twelve on one 





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slide ; in the others, not so numerous. The worms were not 
regularly encysted but coiled up between the fibres. When 
placed on the warm stage, they displayed movements. 

All the animals examined were from Western Canada. 

Oompariaon of local with foreign records. — As the following 
figures show, the record here, 1 in 250, is by no means high. 
Thus, in Boston, Mr. Billings examined over 6,000 animals, and 
in the different groups the ratio ranged from 1 in 17 to 1 in 44. 
All of these animals were from the Western States. In Chicago, 
one series gave 1 in 49.8. In Prussia, where a very thorough 
and systematic pork inspection is carried out, in the year 1876 
only 1 in 2,000 was found affected, and in 1877 about 1 in 

Trichinosis in Canada. — Remarkably few cases of trichina 
infection are known to have occurred in this country. In 1869 
nine persons were attacked in Montreal after eating of fried ham, 
which was ascertained to be trichinous. They presented severe 
gastro-intestinal symptoms, and the constitutional disturbance in 
moderate grade. None of them died. The diagnosis was corro- 
borated by the microscopic examination of a portion of muscle 
harpooned from one of the patients.* In 1868, three members 
of a family in Hamilton were attacked after eating portions of an 
infected ham. Two of these, the mother and daughter, died ; 
the father recovered. At post-mortems and in the dissecting- 
room, it is not uncommon to find the muscles full of calcified 
cysts containing the worms or their remnants. These little bodies 
had been recognized for years before Zenker's discovery con- 
nected them with an antecedent disease. Probably many isolated 
cases occur which are mistaken for acute rheumatism or typhoid 
fever. In between 800 and 900 autopsies made by Dr. Osier, 
four bodies have been found trichinous, the cysts in each instance 
calcified, and in one the worms were nearly all dead. In the 
other eases the parasites were still living, and with muscle from 
one of them the disease was artificially produced in a rabbit. 
So that in all only sixteen cases of the disease have been recog- 
nized in this country. 

• Canada Midical Journal, 1870. 

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Summary.— So far 13 it is legitimate to draw d-iductions from 
the somewhat limited number of observations, we may say that 
trichinosis is a tolerably common aflfection in Canadian swine, 
though not nearly so frequent as in the neighboring States, still, it 
is much more so than is desirable in the interests of public health. 
Should microscopic examination of the flesh be included in the 
inspection ? is a question which at one 3 arises. In answering 
this, several circumstances must be taken into consideration. In 
the first place, although, per 1,000, a larger number of swine are 
infested here than in Germany, trichinosis in man is with us a 
very rare disease, while in Germany epidemics are of yearly 
occurrence. If we estimate that 100,000 hogs are killed annually 
for the local markets, that would give at least three or four hun- 
dred trichinous animals, whose flesh is consumed by the pork- 
eating members of the community. Then, about 3^ million 
pounds of American pork, representing about 15,000 hogs, have 
been imported into this city during the past year, and as in them 
the percentage of trichinae ^s considerably higher than in Cana- 
dian animals, the probable number of infested carcasses consumed 
does not, at the lowest estimate, fall short of five hundred. Now, 
were the habits of the people of this city similar to those of the 
Germans, t^iere can be no doubt that trichinosis, instead of being 
a rare a.rection, would be extremely common. Fortunately, raw 
or only partially cooked pork is not often eaten here, nor are the 
various kinds of sausages, so dear to the Teuton, m^ich in vogue. 
Knackwiirste and Bratwurate, iorms of sausages which are very 
common, and Mc\i are e&ten either raw or only warmed, have 
been the sources of a large proportion of the known cases oi 
trichinosis in Germany 970 out of 1,267. People here almoot 
invariably fry sausages, and smoked meats are not common, nor 
are they eaten without preliminary cooking. In short, the pro- 
phylaxis of the pot and oven in this country and in the neighbor- 
ing States does more for the public than the most stringent 
inspection, even as carried out in Prussia, where a microscopic 
examination is compulsory. If thoroughly cooked, the trichinae 
are killed, and may be eaten with impunity ; and, fortunately, 
there is a very widespread idea in the community that pork, in 



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all forms, should be well cooked, and to this good custom may be 
attributed the immunity from infection which the public has 
enjoyed. Still, it is by nc means pleasant to think of the quan- 
tity of triohinous flesh wliich is placed on our markets, and which 
probably exceeds the entire amount of pork confiscated for other 
causes. The diflBculties in the way of systematic inspection are 
now, under the ^ battoir By-law, greatly lessened, but to subject 
the flesh of every hog killed to microscopic examination would 
require a staff of trained inspectors and an increased expenditure 
such as our civic authorities would not likely incur. Moreover, 
considering the rarity of cases of infection, it may be just as well 
to leave the matter to the cooks of the community, who have so 
long and so faithfully protected us, with this injunction, " See 
that all pork is thoroughly roasted, fried, or boiled." 


This parasite of pork is not so formidable as the trichina, but is 
more common and a more frequent exciter of disease. It is the 
larval or immature form of one of the tapeworms of man, and is 
popularly known as the " measle " or cystic worm, and an in- 
fested animal or its flesh is said to be " measley." In this 
country man is infested with two chief forms of tapeworm, the 
Tcenia solium and the Taenia saginata — the former derived 
from measley pork, the latter from measley veal or beef; hence 
the one is often call? ^ the pork and the other the 6ee/ tapeworm. 
The life history of the Tcenia soliiirr, is as follows : — the adult 
worm occupies the small intestine of man, and attains a length 
of from 12 to 15 feet, or even longer. The segments of which 
the body is made up progressively increase in width from the 
head, and about the 400th become mature — i.e., the male and 
female generative system which each possesses becomes active, 
and eggs are formed. In a fully grown worm it is estimated 
that there may be about 200 ripe segments full of ova, the 
number in each one reaching probably as high as fifty thousand. 
The hinder segments of a tapeworm are constantly shed, or, 
indeed, may detach themselves, at the rate of 3 or 4 per diem, 
and pass away in the faeces. The eggs are small, round, yiy of 

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an inch in diameter, and each one contains in its interior a little 
body known as the six-hooked embryo. For their further growth 
it is necessary that they reach the interior of some animal in 
which they can develop. The hog is the most suitable, and 
usually furnishes the means for the subsequent growth of the ova, 
though the eggs may be accidentally ingested by man and de- 
velop within him, but this rarely happens. It is not difficult to 
understand how hogs become infested ; they are such dirty 
feeders that nothing is refused, and even human excrement is 
greedily eaten. In country places, a single case of tapeworm 
may serve to infest many hogs, as the ripe segments constantly 
pass with the faeces, and one or two will suffice to produce the 
mischief. The eggs in the stomach of the pig are digested, and 
the little six-hooked embryos, in this way set free, immediately 
begin to bore through the walls, and, entering the vessels, are 
carried to all parts of the system, lodging particularly in the 
liver and muscles ; others pass through the coats of the bowels 
into the peritoneum and omentum, and may reach the muscles 
in this way. In these various parts the little embryos gradually 
develop into cysticerci or " measles," and an animal so affected 
is said to be measled. It takes about three months for this pro- 
cess, and when completed, the cysticerci present the appearance 
in the flesh of greyish-white rounded bodies from one-tenth to 
one-sixth of an inch in diameter, situated between the fasciculi 
of muscles, and can be picked out, leaving little holes or 
depressions. When abundant, they give a very characteristic 
aspect to the flesh, which is quite unmistakeable. In the liver 
they may attain a larger size, and in the loose tissues of the 
omentum and peritoneum they are often found the size of a wal- 
nut. The cysticercus or measle is enclosed in an external sh'^ath, 
which, when open, gives exit to a cystic or bladder-like body, 
which requires careful dissection to make out the structure. It 
presents a head similar in all respects to that of the adult tape- 
worm from which the egg was derived, presenting four sucking 
disks and a circlet of booklets. A narrow neck succeeds the 
head, and beyond this there is a bladder-like body called the 
caudal vesicle. 

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If flesh containing these " measles " is eaten raw or only par- 
tially cooked, tapeworm is liable to result. The cyst wall enclos- 
ing the cysticerci is digested away, the bladder worm set free, 
and passes into the intestine, where the head fixes itself firmly 
by means of the sucking disks and booklets. The caudal vesicle 
is digested away, and by a process of budding the segments are 
gradually formed. In about two months the worm has at- 
tained maturity, and segments are discharged containing thou- 
sands of eggs, ready for development in the body of the first 
pig that accidentally ingests the segments. 

Local Record. — Of 1037 hogs examined, 76 were infested — 
i.e., 1 in 13.6. Only the livers were inspected, as it was impos- 
sible to examine the flesh thoroughly. The numbers varied from 
one or two to many dozen, and in most instances they were fully 
developed. The liver is more likely to be affected than the other 
parts, but the occurrence in this organ is a proof that the animal 
has been exposed, and should lead to a thorough examination of 
the flesh. 

In order to obtain evidence of the extent to which " measled" 
meat produces disease — i.e., tapeworm — in the community, we 
issued a circular to the city physicians asking the number of 
cases under treatment. Replies were returned by thirty-four 
doctors who reported sixty-two cases. At the Smith Worm 
Company's office, Bleury Street, about two new cases a week 
are treated ; some of these, doubtless, come from the country, 
but we shall probably be within the mark if we estimate the 
number in the city as not far short of 200. How many of these 
are due to eating ineasley veal or beef, and how many to 
measley pork, wc can.iot say, but from the specimens exam- 
ined it would seem that the beef tapeworm (T. saginata) is the 
more prevalent. Not that the pork raeaslo is uncommon ; the 
record above given shows just the contrary. To explain the 
greater frequency of T. m(jinata, wo must supi)use either that 
the beef measle occurs in greater proportion, or else the pork is 
more thoroughly cooked than the beef or veal. Then, too, much 
less pork is eaten fresh, and the salting and pickling processes 
are usually sufficient to destroy the measles. A point of in- 



terest is the temperature necessary to kill them. The obser- 
vations of Professor Perronicito prove that they are invariably 
killed by a heat of 50°C. or 122*F. Indeed they were swal- 
lowed with impunity by his students after exposure to a tempera- 
ture of 11 3°F. 

Fortunately, the presence of a tapeworm does not give rise to 
such a formidable affection as the trichina, but the amount of 
suffering and annoyance caused is considerable, and not infre- 
quently an individual has to entertain the troublesome host for 
months or years, so difficult is it in some cases to dislodge the 
worm. ^ 

A thoroughly efficient inspection would diminish greatly the 
number of persons annually infected. Of course a hog might 
contain only a few " measles " deep-seated in the muscles, and 
these could readily be overlooked — indeed would be even on the 
most careful examination. 


The presence of this parasite in the flesh of pork has not the 
direct and close relationship to our individual welfare as the 
trichina or cysticercus, inasmuch as it represents a larval form 
of a tapeworm which infests the dog and wolf — never man. The 
adult worm is very small, not more than a quarter of an inch in 
length, with only four segments, the anterior of which forms the 
head, while the hinder one is mature and contains the ova, which 
are passed in the faeces of the dog, and if swallowed by an animal 
may develop in its organs or tissues into the structures variously 
known as echinococci, hydatids, or acephalocysts. A single egg 
of an ordinary tapeworm, when placed in suitable circumstances, 
develops into a single larva or measle (cysticercus)^ but a re- 
markable peculiarity in the life history of the T. echinococcus is 
that a single egg develops into a large compound and complicated 
cyst, which contains many thousands of larvae — hydatids or 
hydatid heads, as they are called — each of which, if transferred 
to the intestine of a dog, might grow into a tapeworm. Man also 
harbors the echinococci, which may produce very serious or fatal 
disease. In some countries, as Iceland and Australia, this affec- 
tion is very prevalent, and many deaths are annually caused by 




the growth of the hydatids in the internal organs, in which they 
may form large tumors. Man gets infected in the same way as 
the hog by the accidental ingestion of the ova, and the point of 
special interest, in relation to public health, is that the occur- 
rence of echinococci in the hog — and in other animals — 
ensures a constant perpetuation of the species among the dogs 
of a community and a consequent risk to the individuals thereof, 
which will be great in direct proportion to general insanitary 
condition and the liability of the eggs to get into the drinking 

Besult of Examination. — In the 1,037 hogs examined, echino- 
cocci were found in the livers of 31, or 1 in 33.4. The cysts 
ranged in size from a marble to a walnut, and presented an ex- 
ternal fibrous investment, formed from the tissues of the part, 
within which was the cyst proper, which could be readily turned 
out. The ectocyst and endocyst were usually well developed, 
the fluid clear, but in none of those examined microscopically 
were the hydatid heads fully developed. 

Echinococcus disease in man is in this country a very rare 
aifection ; not more than eight or ten cases have been known to 
occur. In the United States it is also uncommon,* and a con- 
siderable number of the reported cases have been in foreigners, 
who probably brought the parasite with them. The immunity 
from the disease which human beings here happily enjoy 
may be explained by the existence on the whole of such sani- 
tary regulations as reduce to a minimum the risk of infection. 
Dogs are not numerous, nor are they so intimately associated 
with the every-day work of the people, as in countries like 
Iceland, where, according to Krabbe, the ratio of canine to 
human population is very large, and an extraordinary number 
of the inhabitants suffer from the affection. The adult worm is 
certainly rare ia oa** dogs ; we have n^vet met with a specimen 
in numerous dissections, but its eidstensc is fully shown by the 
occurrenc^.Qf.tlie; larval form in rtany animals and occasi?. -^lly 
in man. " ' ' . ; ■ 

• On Echinococcus Disease in America, by Wm. Osier, M.D., American 
Journal of Medical Sciences, Oct., 1882. 

mm^j^>~-f- '^^mm% 




1. The investigation shows that the hogs slaughtered for our 
markets present parasites in numbers suflScient to necessitate a 
more thorough inspection than is at present carried out. 

2. As regards Trichina spiralis, which was found in the pro- 
portion of 1 to 250, we are of opinion that, considering the ex- 
treme rarity of cases of trichinosis, and the difficulties attendant 
upon a systematic inspection, a compulsory nicroscopic exami- 
nation of the flesh of every hog killed is not at present called for. 

3. In the case of " measles," the liver should be carefully 
examined, and if present in it, the flesh of the animal should 
receive the special attention of the inspector ; if only in the liver, 
the entire carcass need not be confiscated. 

4. Echinococcus cysts in the liver render that organ unfit for 
food, but in other parts, unless very numerous and disorganizing, 
they may be cut out, and the carcass remain marketable. 

5. The public should be made aware of the possible dangers 
of eating, in any form, raw or partially cooked meat. The best 
safeguard against parasitic affections is not so much inspection 
of the flesh, unless, indeed, this is minutely carried out, as care- 
ful attention to culinary details. 

6. To reduce the number of infested hjgs, greater attention 
should be paid to their hygienic surroundings, particularly in the 
matter of feeding. The danger is not during the period when 
the animals are penned and fed on grain, &c., but when they 
are allowed to roam at large and feed indiscriminately. 

Our thanks are due to the authorities of the Montreal and of 
Dominion Abattoirs who kindly permitted the inspection. 

•, • •